Vapor electric device.



D. MCF. MDDRE.

VAPOR ELECTRIC DEVICE.

APPLICATION FILED JUNE Is. |915.

1 ,255,549. Patented Feb. 5, 1918.

H is Attorneg.

" ing atv East' Orange, 'county of Essex, VStateV STATES-PATENT OFFICE.

\ DANIEL IIoEARLAN MOORE, oir-EAST ORANGE, NEW JERSEY, AssIciNOR To GENERAL ELECTRIC COMPANY; A CORPORATION OE NEW YORK.

-vAIOR ELECTRIC DEVICE.

To all whom 'it may concern.'

y Be it known .that I, DANIEL MCFARLAN MOORE, a citizen of the United States, residof NewJersey, have inventedf'certainnew and useful Improvements in Vapor Electric Devices, of which the following is. a specification.

My present invention relates to devices of the class in which an electrical discharge is caused 4to pass between electrodes in a vessel containing a rarefied gas or vapor and more particularly to devices .of this character in which the electrical discharge is of such a nature that the gas or vapor is rendered luminous and hence the device may be used as a source of artificial light.

An object of my invention is to produce a gaseous conduction device in which the gas pressure is maintained substantially constant by means of an arrangement which automaticall produces more gas in the device as fast as t e gas present therein is used up by the passage of the discharge. A further object of my invention is to produce a device `of this nature which is adapted for operation on constant potential alternating current circuits or on constant current circuits, either alternating or direct.

In carrying-my invention into effect I provide, withln the tube or other receptacle` which serves as a container for thefrarelied gasor-vapor, a quantity of a substance which when'heaea win evolve the desired gas. vI

. tube.

i `heating between the electrodes will decrease and consequently the shunt current will' increase.

lmi

As a result the as evolving material will become more hig ly heated and give o moregas, restoring the pressure in the tube to the desired value.

4 My invention, with further objects andadvantages, will best beunderstood by reference to the followingA description taken in Speeication of Letters Patent.

Application led I une 16, `1915. Serial No. 34,524.

connection with Athe accompanying drawing 1n whlch Flgure 1 is an elevation of a complete lamp constructed in accordance with lamp shown in Fig. 1; Fig; 3 is a diagrammatic representation of t e electrical connections of the lamp, Fig. 4 is a fragmentary view illustrating a ,modified form of electrode, and Fig. 5is across sectional view taken along the line 5.-5 `of Fig. 1.

As indicatedin the drawings mylamp comprises a sealed tube I having at each end thereof similar electrodes. While I have indicated the tube in the present case as being straight it will be apparent that it may be given any form desired to vary the amount of light radiating surface and the light distribution. This tube may be mounted in a metal casing open at the bottom and preferably provided with a reflector on its under side. Since the light giving portionof the tube consists only of that portion between the electrodes the portion ,of the tube containing the electrodes may be entirely inclosed by the casing if desired. The casing 3 may conveniently be attached to the casing 4, which protects the transformer 5 (indicated by dotted lines) by a plug and socket connection 6 which serves also to electrically connect thetransformer and tlre tube. It will of course, be apparent that the casing here shown can be utilized fr other tubular lamps than the one 'illustrated and described herein.

The tube 1` also contains between the electrodes 2 and the sealed ends a quantity of vmaterial which gives oif as when heated. This material is preferab y inclosed in a capsule 7 provided with one or more openings to allow the gas evolved to pass into the' tube 1. A heating coil 8 within the capsule is embedded inthe gasevolving material. While this is the preferred location for the gas evolving material it may equally well e placed in a side tube connected to the main tube 1. In any case it should be so located that it will not be af- Ymy invention; Fig. 2 is a bottom Yview of the fected by-the heat of the discharge between 'indicated in Fig. 3 the heating coils at the ends of the tube are connected in series with each other and with regulating resistances 9 across the secondary 10 O f the transformer in s srsua which-isis shunt was sima which includes the electrodes 2, 2, and the h ated intervening gas column. This transformer is preferably designed so as to have Ylarge leakage between the primary and secondary in order to give a substantially constant secondary current. If desired the regulating resistance may dispensed with by providing extra taps on the secondary of the transformer so that the full secondary voltage will not be applied to the heating circuit.

`Such an arrangement will not alect the series circuits.v

method of operation of the device. While I have'described my device in connection with its'operation on constant potential circuits it will be apparent that it is equally well adaptedV for operation on constant current the transformer a plurality of lamps may be connected in parallel with the secondary of the transformer if desired. Also by placs of a transformer staut potentiaL ing a ballast device, such for example -as an inductance, in series therewith either a single'lamp or a plurality of lamps in parallel may be operated from the secondary giving substantially con- In the form of my invention Aillustrated in Fig. 4 I place a ilamentary portion 1l of4 the electrode in series with the heating coil` .8 in order to heat it to incandescence.

This portion of the electrode will then serve as cathode for the discharge while the remaining portion which is heated only by the discharge vwill be cooler at all times and will .l serve as anode. portion 11 of the electrode will preferably be composed of tungsten orother refractory metal. It will of course be apparent that the filamentary por tion 11 may also be connected in Series with the otherV portion of the electrode so that it will be heated bythe discharge current. The electrodes 2 may be composed of aluminum, tungsten, molybdenum, or other metals, the

. choice of the metal to be use'd depending s to some extent upon the gas which is to be employed in the tube. llhe gas evolving mai terial to beused ofcourse depend upon the gas desired. `If carbon diom'd is to be employedlthe heatingcoils 8 may be emcolor matching equipments inasmuch as iti neon or. other inert bedded in any carbonate which gives off carbon dioxid when heated.` Calcium carbonate (CaCo especially suitable for this purpose. lamp inwhich pure carbon dioxld isemployedis especially valuable for gives a light which isnearer to daylight 'than that from any other'known arluicial source. If nitrogen is to be used the evolving substance may consist of a nitride which gives off nitrogen when heated. If

stance employed may be charcoal, platinum sponge or other material which will absorb 1s equa Although I have shown asingle lamp: connected to the secondary of gasisto bsussd the gas cold and give it o again when The life of a lamp of this type will of course depend upon the' amolmt of gas evolving material which is placed the tube in such a way that it will be heated by the coils 8 as well as uponthe particular material'and gas used. vI have found, however, that such a lamp may be given a. reasonably long life without making the space occupied lby the gas evolving material relatively large in comparison with the light emitting part of the tube.

While rI have describedmy invention with particular reference to one speciic form of lighting1 device, it' will be apparent that it y applicable to anygform of electrical'dlscharge Vdevice in which a discharge take's'place between electrodes in a rarefied gas or vapor and in which 1.o keep the disvcharge constant it is necessary to maintain the gas'or vapor at a substantially uniform density.

What I claim as new and desire secure byLetters Patent of the United States is 1.. The combination in a lgas electric lamp of a tubularA receptacle containing a. rareed gas, electrodes within said receptacle, a

- source of constantcurrent connected to said electrodes and adapted to produce` a luminous discharge through fthe rareeld gas, material within said receptacle which evolves gas when heated, a permanently closed heating'coilembedded in said gas evolving material, anda closed circuit in shunt to said Y electrodes which includes saidlheating coil, Athe resistance of said circuit being soadjusted vthat the current flowing therein will vary' in such a way as to keep the density of the gas in said receptacle substantially constant-ri i I' I':

2. The combination in a gaseous conduction device of a receptacle containing a column of rarefied gas, electrodes within Ysaid receptacle, means for causing a discharge current to pass through saidgas column between said electrodes, Ymaterial with-v in .said receptacle which evolvesV gas 'when heated, a heating coil embedded in said- 'gas source of constant current connected to said electrodes to produce an eledrial discharge through the 'rareed gas, a second receptacle in communication with the irst recepf` tacle and containing a material which evolves gas. when heated, and a heating circuit in shunt to ythe circuit between saidelectrodes for heating: the gasv evolving'material to 2.5' electrical discharge and containing source of constant current connected to saidl such a degree as to maintain the density of the gas substantially constant.

4:. The combination in a gaseous conduction device of a receptacle containing a rareed gas, electrodes within said receptacle, a

electrodes to produce an electrical discharge through the rareied gas, a second receptacle in communication with said first receptacle but; removed from the path of the electrical discharge and containing a material which evolves gas when heated, and a permanently Yclosed heating circuit in shunt to the circuit between said electrodes for heating the gas evolving material to such a degree as to maintain the density of the gas substantially constant.

5. The combination in a gaseous Vconduction device ofl a receptacle containing a rarefied gas, electrodes within said receptacle, a

source of constantv current connected to said electrodes to produce an electrical discharge through the rareed gas, a second receptacle in communication with therst receptacle but removed from the path of the a mater'ial which evolves .gas when heated, and a Y heating coil embedded in said gas evolvin materialand connected in shunt to the circuit between said electrodes. "Y "15. The combination in a gas electric lam-p of a tubular receptacle containing a rareed gas, electrodesfnear the ends of said receptacle, a source of constant current connected to'said electrodes to produce a luminous 'discharge through ,the rareed gas, va psecond receptacle with said first receptacle,

between one of the electrodes and the corresponding end of the receptacle, containing a 'material which decomposes when heated andn 1 evolves gas and a heating coil embedded in said gas evolving material and connected in shunt -to the circuit between the electrodes.

- 7; The combination in a gaseous conduction device of a receptacle containing a rarelied gas, electrodes within said receptacle having ilamentary portions,.a source of constant current connected to said electrodes to produce an electrical discharge through the rareed gas, material within said receptacle which evolves gas when heated, a heating coil embedded in said gas evolving material and a heating circuit in shunt to the circuit between said electrodes lfor'heating the gas evolving `material and the lamentary portions of the electrodes.' l

8. A vacuum. tube having therein gas evolving material and a heating element embedded in said gas evolving material, said heating element being connected in a pemanently closed circuit in shunt to said tu e.

9. A vacuum tube having internal electrodes, a capsule therein containing gas evolving material land a heating element embedded in saidgas evolving material, said heating element being connected in a pelrmanently closed circuit in shunt to said tu e.

10. A vacuum tube having internal electrodes, a receptacle' containing gas evolving material in communication with the interior of said vacuum tube and a heating element embedded in said gas evolving material, said heating element being connected in a permanently closed circuit in shunt to said tube.

A l1. A.vacuum tube having internal electrodes and containing a gas whichjis rendered luminous by an electrical discharge between saidclectrodes, a receptacle in communication' with the interior of said vacuum tube and containing a material which, when heated, evolvesV a gas suitable for replenishing the gas in the tube and a heating element embedded in said gas evolving material, and connected in a closed shunt circuit to said electrodes.

' Inwitness whereof, I have hereunto set my hand this 14th day of June, 1915..

DANIEL MQFARLAN MOORE. 

